This is a combination of my favorite key lime pie recipes. I love key lime pie, but many times find it too tart for my liking; the cream cheese in this recipe is the perfect foil to the lime juice and contributes an amazing creaminess. And the sour cream topping MAKES this pie - don't skip it! The only shortcut I take is to sometimes use a store-bought graham cracker crust....shhhhh, don't tell my family! Cooking time includes 2 hours chilling time in the refrigerator.